The information provided here is meant to give you a general idea about each of the medications listed below. Only the most general side effects are included, so ask your doctor if you need to take any special precautions. Use each of these medications as recommended by your doctor, or according to the instructions provided. If you have further questions about usage or side effects, contact your doctor.

Since there is no known cause of
IBS, medications are used to treat specific symptoms. There are several types of medications that are thought by some doctors to be helpful. But, not all of the medications listed below are of proven value in treating symptoms of IBS. In some cases, your doctor may recommend that you take a combination of medications.

Cisapride, a drug used to increase bowel motility, has been removed from the US market. But, it may still be prescribed in special cases.

Possible side effects of domperidone and metoclopramide include:

Headache

Dry mouth

Stomach ache

Diarrhea

Restlessness

Sleep disruption

5-hydroxytryptamine (5-HT) Antagonists and Agonist

Common name includes:
alosetron

Alosetron may be prescribed to treat diarrhea, as well as general IBS symptoms, such as abdominal pain.

Possible side effects include:

Severe constipation

Nausea and vomiting

Stomach pain

Anti-Anxiety Medications

Common names include:

Diazepam

Alprazolam

Lorazepam

These medications may be prescribed to reduce anxiety associated with IBS.

Possible side effects include:

Drowsiness

Confusion

Impaired memory

Heart rate changes

Sleepiness

Constipation

Diarrhea

Rashes

Dry mouth

Antibiotics

Common names include:
rifaximin

In some cases, antibiotics are recommended to treat IBS symptoms, such as bloating and diarrhea.

Miscellaneous Medications

Lubiprostone

Lubiprostone may be useful in managing IBS when constipation is the primary symptom and fiber is unsuccessful.

Possible side effects include:

Nausea and vomiting

Headache

Stomach ache

Heartburn

Diarrhea

Linaclotide

Linaclotide may be used to increase the amount of fluid in the intestines.

Possible side effects include:

Diarrhea

Gas

Stomach ache

Over-the-Counter Medications

Fiber Supplements

Common names include:

Psyllium

Bran

Polycarbophil

Methylcellulose

Dietary fiber is the undigestible part of plants considered important in the optimal functioning of the digestive tract. Initially, fiber supplements may cause bloating and gas, which usually subside within a few weeks. Increase your fiber intake gradually. Drink plenty of water as you increase your fiber to promote regularity.
Bran may be less effective than psyllium or other “soluble” fibers.

This drug breaks up bubbles in the stomach to make it easier for gas to exit upward, before it gets into the intestines.

Probiotics

Probiotics
are "friendly" bacteria such as acidophilus, which is found in yogurt. Probiotics may help improve abdominal pain and other symptoms of IBS. These bacteria can also be bought as a supplement. Talk to your doctor if you are interested in adding probiotics to your diet.

Pain Relievers

Common names include:
acetaminophen

Acetaminophen may relieve abdominal pain.

When to Contact Your Doctor

If the medication is not working

If you are getting worse

If you are having new symptoms

Special Considerations

If you are taking medications, follow these general guidelines:

Take the medication as directed. Do not change the amount or the schedule.

Ask what side effects could occur. Report them to your doctor.

Talk to your doctor before you stop taking any prescription medication.

Plan ahead for refills if you need them.

Do not share your prescription medication with anyone.

Medications can be dangerous when mixed. Talk to your doctor if you are taking more than one medication, including over-the-counter products and supplements.

Please be aware that this information is provided to supplement the care
provided by your physician. It is neither intended nor implied to be a
substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER
IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the
advice of your physician or other qualified health provider prior to
starting any new treatment or with any questions you may have regarding a
medical condition.